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CONVERSATIONS ON 



had been thrown upon the wall when it was 

 wet, and had afterward dried there. Here is 

 a picture of one of these nests. 



Exterior wall of Mason-bee's Nest. 



You see there is a small hole in it ; this leads 

 to a cell inside about an inch deep, and shaped 

 exactly like a lady's thimble ; the inside of 

 this cell is polished smooth, and appears like 

 a wall of plaster, except that it has little yel- 

 low stains upon it. Here is the bee that 

 makes it. 



Mason-bee. Natural size. 



In making this mortar to build with, the bee 



